Taylor Philip G, Cleveland Cory C, Wieder William R, Sullivan Benjamin W, Doughty Christopher E, Dobrowski Solomon Z, Townsend Alan R
Institute for Arctic and Alpine Research, University of Colorado, Boulder, CO, USA.
Department of Ecosystem and Conservation Sciences, University of Montana, Missoula, MT, USA.
Ecol Lett. 2017 Jun;20(6):779-788. doi: 10.1111/ele.12765. Epub 2017 Apr 17.
Tropical forests dominate global terrestrial carbon (C) exchange, and recent droughts in the Amazon Basin have contributed to short-term declines in terrestrial carbon dioxide uptake and storage. However, the effects of longer-term climate variability on tropical forest carbon dynamics are still not well understood. We synthesised field data from more than 150 tropical forest sites to explore how climate regulates tropical forest aboveground net primary productivity (ANPP) and organic matter decomposition, and combined those data with two existing databases to explore climate - C relationships globally. While previous analyses have focused on the effects of either temperature or rainfall on ANPP, our results highlight the importance of interactions between temperature and rainfall on the C cycle. In cool forests (< 20 °C), high rainfall slowed rates of C cycling, but in warm tropical forests (> 20 °C) it consistently enhanced both ANPP and decomposition. At the global scale, our analysis showed an increase in ANPP with rainfall in relatively warm sites, inconsistent with declines in ANPP with rainfall reported previously. Overall, our results alter our understanding of climate - C cycle relationships, with high precipitation accelerating rates of C exchange with the atmosphere in the most productive biome on earth.
热带森林主导着全球陆地碳（C）交换，亚马逊盆地近期的干旱导致陆地二氧化碳吸收和储存短期下降。然而，长期气候变化对热带森林碳动态的影响仍未得到很好的理解。我们综合了来自150多个热带森林站点的实地数据，以探究气候如何调节热带森林地上净初级生产力（ANPP）和有机质分解，并将这些数据与两个现有数据库相结合，以探究全球气候与碳的关系。虽然先前的分析侧重于温度或降雨对ANPP的影响，但我们的结果突出了温度和降雨之间的相互作用对碳循环的重要性。在凉爽森林（<20°C）中，高降雨量减缓了碳循环速率，但在温暖的热带森林（>20°C）中，它持续增强了ANPP和分解。在全球范围内，我们的分析表明，在相对温暖的地区，ANPP随降雨量增加，这与先前报道的ANPP随降雨下降的情况不一致。总体而言，我们的结果改变了我们对气候与碳循环关系的理解，高降水量加速了地球上最具生产力生物群落与大气之间的碳交换速率。
